OFFSET
1,1
COMMENTS
Companion sequence to A185069.
EXAMPLE
5*6^1-1 = 29 is prime and therefore a term.
7*6^2-1 = 251 is prime and therefore a term.
17*6^13-1 = 222031798271 is prime and therefore a term (see also its companion in A185069).
MATHEMATICA
maxM = 4; p = Prime[Range[PrimePi[2*6^maxM]]]; Sort[Flatten[Table[Select[p + 1, PrimeQ[#/6^k] &], {k, 0, maxM}] - 1]] (* T. D. Noe, Feb 28 2011 *)
PROG
(Magma) IsA186782:=function(n); k:=n+1; while k mod 6 eq 0 do k:=(k div 6); end while; return IsPrime(k); end function; [ n: n in PrimesUpTo(3000) | IsA186782(n) ]; // Klaus Brockhaus, Mar 01 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Gilbert Mozzo, Feb 26 2011
STATUS
approved